Apparatus for stitching a continuously running web

ABSTRACT

Apparatus for high speed stitching of a continuously running web, comprising a rotatable stitching cylinder and mounted therein a stitching arm taking along a cut wire length from a cutting device, forming said wire length in to a staple by coaction with a forming device, and finally pressing the staple through the web to be stitched and clinching the staple by coaction with a clinching means disposed on the opposed side of the web when the stitching arm and the web are maintained at the same lateral speed.

Unie States Patent 1 1 Noren 1 Oct. 2, 1973 [54] APPARATUS FOR STllTCHIN G A 2,224,743 12/1940 Nolan 227/81 CONTINUOUSLY RUNNING WEB 1,054,043 2/1913 Sheldon t. 2,818,568 1/1958 Turrall et al 1. 1 1 lnventorr Ame llhgvar Norm, Stamgatan, 3,186,617 6/1965 Fischer Sweden 2,717,383 9/1955 Stobb 227/81 [73} Assignee: Toleransalttielboiaget, Alvsjo, I

Sweden Primary Exum11zer-C|ranv11le Y. Custer, .lr.

Attorney-Darby & Darby [22] Filed: Mar. 31,1971

[21] App]. N0.: 129,795 [57] ABSTRACT Apparatus for high speed stitching of a continuously [30] Foreign Application Priority Data running web, comprising a rotatable stitching cylinder Apt 6 1970 Sweden u 4664/70 and mounted therein a stitching arm taking along a cut wire length from a cutting device, forming said wire 52 us. c1. 227/81 length in to a Staple by Coaction with a forming device, 51 1m. (:1 B27t 7 12 and finally pressing the Staple through the web to be [58] Field of Search 227/81 Stitched and clinching the Staple: y CO-action w clinching means disposed on the opposed side of the [56] References Cited web when the stitching arm and the web are maintained UNITED STATES PATENTS at the same lateral speed.

3,040,324 6/1962 Worthington et a1 227/81 7 Claims, 4 Drawing Figures PATENTEDUBT 2W5 3.762.622

' SHEET 10F 3 LD N YIINVENTOR ARNE INGVAR NOREN ATTORNEYS PATENTEDBCI '2 ma SHEET 2 BF 3 INVENTOR ARNE INJGVAR NOREN ATTORNEYS PATENTEDW 2W 3.762.622

SHEET 30F 3 co l O! o O) L O 3 N g/ INVENTOR ARNE INGVAR NOREN BM, a

ATTORNEYS APPARATUS FOR STITCIIING A CONTINUOUSLY RUNNING WEB BACKGROUND OF THE INVENTION In one form of a known apparatus of the aforesaid kind for stitching paper webs, the stitching arm carrying the staple is mounted so as to be pressed resiliently into the stitching cylinder. In the contact point between the stitching cylinder and the web to be stitched, the stitching arm by contact with the web is pressed resil iently into the stitching cylinder and at the same time the staple carried by the arm penetrates through the web. Such an apparatus has a limited operation speed, because the strokes of the stitching arm against the web increase with the higher number of revolutions of the stitching cylinder and thereby crush the paper web.

There are also punching mechanisms known, in which the arm or die carrying the staples is pressed out against the web in the moment of stitching. This mechanism also has the disadvantage of increasing the strokes against the web with increasing speed.

A further disadvantage of the stitching apparatus of the aforedescribed kind is that there is a small difference in lateral speed between the stitching arm and the web in the stitching moment. This difference in speed has its reason in that the stitching arm moves along a curve, but the web moves in a straight line. Due to this difference in speed, the staple is turned during the stitching operation and, furthermore, the staple does not safely meet the web at a suitable angle upon its first contact with the web.

SUMMARY OF OBJECTS The present invention has as its object the elimination of the disadvantages of the conventional prior apparatus and also to produce a stitching apparatus adapted to operate at high stitching speeds. This is achieved preferably by providing a stitching arm or staple carrying arm which is mounted on a rotating drive cylinder so as to turn or revolve therewith, and which is slidably arranged within a die member so as to be gradually retractable relative to the periphery of the drive cylinder whereby the outer end of the arm traces a substantially linear path as it is moved in the vicinity of the paper web. A pivotally mounted lever arm is connected to the staple carrying arm and is adapted to be manipulated by a fixed cam and cam follower so as to cause the staple carrying arm to be retracted. The relative speeds of the drive cylinder and web as well as the particular shape of the cam surfaces are selected such that the staple carrying arm and staple attain a peripheral substantially linear speed during stitching which is substantially equal to the speed of the web. The die member is preferably adapted to engage the staple to remove it from the carrying arm and to press it through the web as the arm is retracted.

DESCRIPTION OF THE DRAWINGS The invention is described in greater detail in the following, with reference to a preferred embodiment.

FIG. 1 shows in a schematic way a lateral view of the stitching apparatus, in which for the sake of clearness several details have been omitted, and the Figure only shows a basic sketch,

FIG. 2 shows a plane view, partially in section, taken along the line AA in FIG. I.

FIG. 3 shows a stepping device for feeding and cutting the wire forming the staple,

FIG. 4 shows a detail in the feeding device taken along the line B-B in FIG. 3.

PREFERRED EMBODIMENT FIG. 1 shows in a schematic way the apparatus ac cording to the invention for stitching a continuously running web P, for example a paper web or the like, comprising layers or sheets to be stitched together. The web P moves continuously in the direction of arrow I, i.e. downwardly in the Figure, between a stitching cylinder 20 carrying the stitching arm 13 and a cylinder 26 on the opposite side of the web, which cylinder 26 carries an anvil 27 against which the staple is clinched. The cylinders 20 and 26 rotate continuously in contrary directions, as indicated by the arrows in the Figure.

The staple to be pressed into and clinched in the web, is engaged by the stitching arm in a position in the direction of rotation before the stitching place and is formed in said position, as described in the following. On the side of cylinder 20 opposed to the web P, a cutting device is provided which, for example, may be of the type having a rotary tool 10. Said tool coacts with a stationary cutting edge 11 for cutting off a wire length 12, which is fed in in a direction perpendicular to the plane of the Figure by means of a feeding device, which is described in greater detail with reference to FIG. 3. The cutting tool 10 rotates in the direction of arrow II and is provided with several cutting edges or teeth, which subsequent to the cutting of a wire length 12 transport this length to a position at which the tool 10 is substantially horizontal and the wire length 12 is retained in the cutting device by means of one or several spring leafs 14 forming a wire path extending to a forming roll 16. The wire length located between the spring leafs l4 and a stationary block 15 is carried by the stitching arm 13, which is provided with projecting legs 13a engaging between the spring leafs 14 for continued transport of the wire. The operation of the cutting apparatus is as follows: The cutting tool 10 cuts a piece of wire 12 and carries this piece of wire by its upward rotation movement to aposition. where the cut wire length is held between the block 15 and the spring leaves 14 by friction due to the spring bias. The wire length is subsequently engaged by the legs 13a of the stitching arm 13. Continued movement of the stitching arm 13 due to rotation of the drive cylinder 20 causes the wire length 12 to be transferred upwardly between the block 15 and the spring leaves 14 into position to be engaged by the staple forming roll 16. As indicated in FIG. 2, the staple forming roll 16 has a substantially U-shaped periphery with radially projecting legs 16a. As the stitching arm 13 moves the cut wire length into engagement with the roll 16, the projecting legs 16a enter the grooves 17 in the stitching arm between the wire supporting legs 13a thereby forcing the cut wire length to be formed into the shape of a staple 12a. At this time, the crown of the newly formed staple is pressed beneath the resilient finger 18 by the leg 16a of the roll and is held between the finger l8 and a part of the arm 13 underlying the finger 18, as is explained below.

The finger 18 consists of a length of resilient material such as spring steel or rubber which is attached at one end to the stitching arm 13 and which protrudes longitudinally outwardly relative to the stitching arm substantially parallel to and between the outer ends of the legs 13a. The stitching arm 13 is also provided with an integral supporting element (not shown) which underlies the finger 18. As the wire length 12 is being formed into a staple 12a by the legs 16a of the forming roller 16, the crown of the staple is pressed beneath the resilient finger 18 and is held between the finger 18 and the supporting element.

Upon continued rotation of the cylinder 20, the stitching arm 13 carries the staple 12a to the position shown in FIG. 1 where it is to be pressed into the web P. According to the invention, the stitching arm 13 is mounted movably in a die body 241, which is mounted rotatably in the cylinder at 19. The die 24 is so designed that part of the same, indicated by reference numeral 24a (FIG. 2) is located between the legs 13a of the stitching arm 13 so that when the die 24 is brought into the vicinity of the web P the part of the die body 24a forms a thrust for the crown portion of the U- shaped staple 1221 when the staple is being pressed into the web P, whereby the staple upon retracting of the arm 13 is released from the engagement in the resilient finger 18 of the stitching arm. The inner end of the stitching arm is hinged at 23 to an angular lever 22, which is pivotally mounted at 21 in the cylinder 20 and at its other end carries rotatably one or several rollers 33 coacting with a stationary cam surface provided to the side of the cylinder 20. The cam surface thereby can serve two stitching apparatus arranged on both sides of the surface, or a single stitching apparatus located on one side.

By positive control of the longitudinally movable and simultaneously rotatable stitching arm 13 by means of the cam surface 25, and by a suitable choice of the curve of the cam surface, the staple can be guided at the penetration of web P, so that the staple always meets the web at a suitable angle, irrespective of the operation speed. In operation, the cylinder 21) is rotated at a continuous speed of a predetermined number of rotations per hour. As indicated above, both the lever arm 22 and the die body 24% are pivotally mounted on the cylinder 20 at points indicated by reference numerals 21 and 19 respectively. Thus, both the lever arm 22 and the die body 24, as well as the stitching arm 13, are carried, or revolve, around the axis of rotation of the cylinder 20 as the latter rotates during the operation of the machine. The cam rollers 33 are laterally offset from, but are connected to, the lever arm 22 and are also revolved around the rotational axis of the cylinder 20 as the latter rotates. Since the cam rollers 33 are in continuous engagement with the laterally offset fixed cam surfaces 25, the lever arm 22 can be made to pivot or rock back and forth around its pivot point 21 as the cylinder 20 rotates, depending upon the shape of the cam surfaces. For example, with reference to FIG. 1, cam rollers 33 are shown to be moving along a particular slope of the cam surface 25 which carries them closer to the circumference of the cylinder 20. As the cam rollers move toward the periphery of the cylinder 20 the lever arm 22 is pivoted in a clockwise direction around its pivot point 21, thus causing the stitching arm 13 to be retracted inwardly through the passage in the die body 24, thereby moving away from the web P. Conversely, as the cylinder 20 continues to rotate in the direction indicated the rollers 33 are moved by the cam surface 25 in a gradual inward spiral. This causes the lever arm 22 to pivot in a counterclockwise direction thereby extending the stitching arm 13 into proper position to pickup a new staple from the cutting device 10.

In accordance with the present invention, the shape or curve of cam surfaces 25 is selected such that, at the beginning of the stitching phase of operation, as the stitching arm 13 brings a staple into proximity to the moving web P, the lever arm 22 is being manipulated by the cam so as to pivot gradually in a clockwise direction thus causing the stitching arm 13 to be retracted as described above. During the stitching phase, as the arm 13 is gradually retracted, it preferably moves, relative to the die 24, along a path generally perpendicular to the plane of the web P.

In effect the outer extremity of the stitching arm 13 which carries the staple, is moving, during the stitching phase, along a substantially linear path parallel to the web P. Stated another way, the locus of points generated by the outer end of the stitching arm 13 and its staple during the stitching phase is substantially a straight line. The rotational speeds of the cylinders 20 and 26 are selected so that this substantially linear movement of the arm 13 in the vicinity of the web P is at a velocity which corresponds substantially to the velocity with which the web is moving. Since the staple obtains a lateral speed substantially equal to that of the web P, there is little or no twisting and turning of the staple 12 as it enters the web, and thus the web is not damaged.

The die 24? does not move relative to the cylinder 20, thus the gradual retraction of the stiching arm 13 relative to the die 24 causes the portion 24a of the latter to engage the staple and to press the staple gradually through the web P.

Applicant has achieved recurring alignment of the anvil 27 with each staple pressed through the paper web by the die 24, by proper selection of the respective diameters of the cylinders 20 and 26. Since the periph eral speed of the stitching arm 13 is decreased during retraction (owing to its essential linear rather than arcuate peripheral path), the diameter of the cylinder 26 is slightly less than the diameter of the cylinder 20 so that the angular velocity of the anvil 27 will be substantially matched with the speed of the web P and that of a staple 12a carried by the arm 13 during the stitching phase of the operation. Although the angular velocity of the stitching cylinder 20 is greater than that of the folding cylinder 26, both cylinders are rotated at the same number of revolutions per hour so that there is no risk that the anvil on the folding cylinder will be out of phase with the stitching arm 13.

For feeding the wire 12 to the cutting device 10, a feeding device with two rollers 28, 23a, as shown in FIG. 3, is provided, which rollers are so arranged that the wire is clamped and advanced between the peripheries of the rollers. The periphery of one roller 28 however, being broken at 29, the feed is interrupted temporarily every time the wire is cut off, for example four times per revolution of the rollers 28, 28a.

The broken roller 28, as appears from FlGS. 3 and 4, can be designed so as to have twice the width and to include recesses or interruptions 29, 30 of different length arranged to the side of each other. Hereby it is possible, by axial displacement of the roller, to inter,- rupt the feed of the wire to the cutting device, for example, twice per revolution of the roller 28, and for a longer period, so that the stitching takes place, for example, only during every second revolution of the cylinder 20.

FIG. 3 also shows an electromagnet 31, by which the wire feed can be interrupted, if desired, by lifting up the roller 28. The electromagnet 31 thereby can preferably be connected to a switch 32 actuated by a springloaded wire control 34. The wire coming to an end, this is sensed by the wire control 34 rolling against the wire, whereupon the wire control 34 connects the switch 32, which supplies current to the electromagnet 31 for lifting the roll 28, and the feeding is interrupted.

What I claim is:

1. Apparatus for stitching a continuously running web, comprising:

a first rotary member;

a second rotary member substantially adjacent said first member and having a rotational axis substantially parallel to the rotational axis of said first member, the web passing between said first and second members and having a predetermined linear velocity;

a staple holding arm mounted on said first member to turn therewith and being adapted to support a staple for insertion through the web during a stitching phase of rotation of said first member, said arm being movable back and forth along a line generally perpendicular to the web during said stitching phase;

means operatively connected to said arm for manipulating movement thereof along said line, said arm being radially farther from the rotational axis of said first member at the beginning of said stitching phase than at completion of said stitching phase and having a linear velocity during said stitching phase substantially corresponding to the linear velocity of said web;

means mounted on said first member for engaging the staple during said stitching phase to remove the staple from said arm and to press the staple through the web; and

an anvil mounted on the circumference of said second member and engageable with the staple to clinch the staple during said stitching phase.

2. The apparatus of claim 1 in which said first and second rotary members are substantially cylindrical, the diameter of said first rotary member being greater than the diameter of said second rotary member.

3. The apparatus of claim 2 in which said means for manipulating the staple holding arm comprises a lever member activated by a cam.

4. The apparatus of claim 2 comprising in addition means for forming a staple comprising a wire feeding means, a rotary cutting tool for cutting the wire, a U shaped forming roll for forming said wire into a staple, the wire being transported to the stitching location by the staple holding arm, the feeding means being inoperative during the cutting of the wire.

5. The apparatus of claim 4 in which the wire feeding means comprises two rollers between the surfaces of which the wire is gripped, one of the rollers having a circumferential depression on its surface so that the feeding ceases during the time that the wire is in one of the depressions,

6. The apparatus of claim 5 in which at least one of the rollers is cylindrical and has a plurality of depressions of different lengths along the: outer circumference of the roller, each depression occupying a distinct circumferential plane.

7. The apparatus of claim 3 in which one of the roll ers is movable out of contact with the wire when a sensing means senses the end of the wire. 

1. Apparatus for stitching a continuously running web, comprising: a first rotary member; a second rotary member substantially adjacent said first member and having a rotational axis substantially parallel to the rotational axis of said first member, the web passing between said first and second members and having a predetermined linear velocity; a staple holding arm mounted on said first member to turn therewith and being adapted to support a staple for inSertion through the web during a stitching phase of rotation of said first member, said arm being movable back and forth along a line generally perpendicular to the web during said stitching phase; means operatively connected to said arm for manipulating movement thereof along said line, said arm being radially farther from the rotational axis of said first member at the beginning of said stitching phase than at completion of said stitching phase and having a linear velocity during said stitching phase substantially corresponding to the linear velocity of said web; means mounted on said first member for engaging the staple during said stitching phase to remove the staple from said arm and to press the staple through the web; and an anvil mounted on the circumference of said second member and engageable with the staple to clinch the staple during said stitching phase.
 2. The apparatus of claim 1 in which said first and second rotary members are substantially cylindrical, the diameter of said first rotary member being greater than the diameter of said second rotary member.
 3. The apparatus of claim 2 in which said means for manipulating the staple holding arm comprises a lever member activated by a cam.
 4. The apparatus of claim 2 comprising in addition means for forming a staple comprising a wire feeding means, a rotary cutting tool for cutting the wire, a U-shaped forming roll for forming said wire into a staple, the wire being transported to the stitching location by the staple holding arm, the feeding means being inoperative during the cutting of the wire.
 5. The apparatus of claim 4 in which the wire feeding means comprises two rollers between the surfaces of which the wire is gripped, one of the rollers having a circumferential depression on its surface so that the feeding ceases during the time that the wire is in one of the depressions.
 6. The apparatus of claim 5 in which at least one of the rollers is cylindrical and has a plurality of depressions of different lengths along the outer circumference of the roller, each depression occupying a distinct circumferential plane.
 7. The apparatus of claim 3 in which one of the rollers is movable out of contact with the wire when a sensing means senses the end of the wire. 